staging/lustre/style: removes obsolete EXPORT_SYMTAB macros v2

EXPORT_SYMTAB is obsolete after 2.4 kernel, this patch removes
EXPORT_SYMTAB from the source code again.

Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-1347
Lustre-change: http://review.whamcloud.com/6739
Signed-off-by: Keith Mannthey <keith.mannthey@intel.com>
Reviewed-by: Peng Tao <bergwolf@gmail.com>
Reviewed-by: Liu Xuezhao <xuezhao.liu@emc.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Signed-off-by: Peng Tao <tao.peng@emc.com>
Signed-off-by: Andreas Dilger <andreas.dilger@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>